In a statement, Mayor Daley praised the program and said, “The well-being of cities like Chicago depends to a large degree on how we plan for and deal with global inter-connection.”

Ireland’s ambassador to the U.S., Michael Collins, is among those planning to have his passport stamped “Chicago.” He came last for this year’s St. Patrick’s Day parade. “A wonderful opportunity,” he said by phone Monday from Dublin.

Collins took in Florida, Texas and California on the previous trips and said they let diplomats “experience the wider America,” engage with local leaders and pursue issues such as energy efficiency.